Okay, after looking at all the DIY's for two days straight, I can tell a few things that are not mentioned.
If you are going to install an aftermarket radio in a later MKIV or MKV, there are two items that are not really mentioned clearly.
One is the antenna adaptor. The correct one is for an ampliefied antenna. From Metra it is an EU-55. The non amplified one, EU-10 will work, but since the anntenna amp is not turned on, reception will suffer.
The second is the CAN line. The OEM radio is turned on by the CAN bus. The ground is pin 12, the BAT is pin 15. There is no accessory to turn off the aftermarket radio, but you have three choices.
Using Metra 80-9003:
1. Hook up the accessory of the radio to the vehicle ignition. Pretty easy and there is a stud underneath the dash.
2. Hook up a relay to the key sense wire (18g brown/red) located in the steering column. You will hook up pin 30 to the red/acc wire; pin 87 to the BAT/yel wire; 85 to ground; 86 to the key sense wire. This lets you use the radio with the car off, but will obviously turn off the radio when you remove the key.
3. Use Metra XSVI-9003 for 2002 and newer cars. It uses a circuit to interface with the CAN bus to turn the radio on. Simple to install, and includes an illumination wire to control a deck's lighting. Will keep the radio on until you open a door and remove the key, but you cannot just turn on the aftermarket radio just by pushing a button in. You still have to enter the key.
As far as kits, the OEM pocket (MKIV) and OEM kit (MKV) work way better than the Metra parts, but the Metra kit will accept a double din, where the OEM kit is for a single din only.
The Monsoon amp is turned on by speaker sense, so no outside connections need be done past the speaker connections at the wire harness adaptor. The stock Monsoon deck is already a high level input to the amp, so no issue shoud arise from a new deck with the stock amp. Past that, you would have to remove the amp and install passive crossovers for the the mid and tweeter; in case you wanted to add an aftermarket amp for better performance.
Modified by ricksterincc at 10:05 PM 2-23-2006
Modified by ricksterincc at 10:12 PM 2-23-2006